This invention relates to annular sealing members and assemblies incorporating them.
The invention provides an annular sealing member one peripheral surface of which has a portion or portions bounded by a cylinder and a single enlarged diameter portion projecting radially beyond the cylinder, the sealing member having an annular sealing edge around its other peripheral surface or around one axial end face of the sealing member.
The invention also provides an assembly comprising two coaxial relatively rotatable parts, one of which has a cylindrical seating surface, and a resilient annular sealing member for sealing an annular gap between the parts, one peripheral surface of which sealing member has a single enlarged diameter portion which is an interference fit in or on the seating surface and the remainder of that peripheral surface is no more than a sliding fit in or on the seating surface, the sealing member also having an annular sealing edge around its other peripheral surface or one axial end face of the sealing member which edge seals with a co-operating surface on the other of the relatively rotatable parts.
In such assemblies, the enlarged diameter portion may be adjacent one end of the sealing member. If this feature is adopted the edge of the sealing member adjacent the enlarged diameter portion may be chamfered to provide a lead for inserting the sealing member into or onto the seating surface. The chamfer angle may be 25.degree. to the horizontal.
Also in assemblies according to the invention, the sealing member may be provided with a reinforcing member extending into or embedded in the sealing member. Preferably, the radial thickness of resilient material of the sealing member covering the outer peripheral surface of the reinforcing member is at least 0.5 mm.
Furthermore, in assemblies according to the invention, said one peripheral surface of the sealing member may be the outer peripheral surface, the sealing edge connected to the body of the sealing member by an integral flexible web and the sealing edge constituting the inner periphery of the sealing member. In such arrangements, a garter spring may be provided around the sealing edge to bias the sealing edge radially inwards.
The two relatively rotatable parts in any of the above assemblies may be the inner race ring and the outer race ring respectively of a rolling bearing.
When the relatively rotatable parts are the inner and outer race rings of a rolling bearing, the seating surface may be provided by a cylindrical recess in the respective race ring which recess extends axially towards the rolling members from one end face of that race ring.
If the latter feature is adopted, the axial length of the sealing ring may be greater than the axial extent of the recess so that a portion of the sealing member spaced axially from the enlarged diameter portion thereof projects axially beyond the said one end face of the race ring, the reinforcing member (if any) being radially inwardly of the said projecting portion or being contained between the axial ends of the recess and spaced from the open end thereof so that axial compression of the projecting part of the sealing member is not osbtructed by the reinforcing member.
It will be appreciated that when the race ring in which the recess is provided, is located in a housing, the projecting portion of the sealing member is intended to be compressed against an end wall of the housing or an adjacent component to effect a seal thereagainst.
Some embodiments of the invention will now be described by way of example and with reference to the accompanying drawings.